NEW YORK – Paul Pierce strolled into the visitor’s locker room armed with a smile Tuesday.

He threw an arm around Phil Lynch, the Celtics’ director of team security, and asked where everyone was, but most were either on the court, in the weight room, or elsewhere. By then, the preseason game here at the Barclays Center wasn’t schedule to tip for about an hour.

No matter. Pierce had come to greet his former teammates before they faced off for the first time since he joined the Brooklyn Nets, and he still planned to do just that.

Pierce found guard Avery Bradley, hugged him, and congratulated him on the recent birth of his son. Pierce asked what Bradley named him. “Avery,” Bradley said. Pierce liked that. Then the 36-year-old forward saw Walter McCarty.

“What up, coach McCarty?” Pierce said before hugging the new Celtics assistant coach and his former teammate.

Pierce then walked toward the back of the room, shouting “Where my boys at?” He disappeared into a room opposite the showers and laughter and high-fives could be heard. Pierce came back out, hugged forward Brandon Bass and a few team staff members, greeted a few Boston-based reporters by name, then walked out.

An hour later here at the Barclays Center, Pierce was the first member of the Brooklyn Nets to be introduced in their starting lineup. Wearing a white No. 34 jersey, he took to center court just before tip-off and chatted and joked some more with the Celtics players.

Then the officials tossed the ball up, starting the game, and Pierce played against the franchise that drafted him in 1998, that he played for in every season since until now, that he won a championship with, and that will retire his number one day.

With seconds remaining in the first half, Pierce stood at the top of the key, ball in his hand, the clock winding down, as usual.

Jeff Green guarded him, and Pierce used a pick-and-roll and cut to the left side of the floor, where he beat Green for a layup.

With that, Pierce scored his first points against the franchise for which he scored 24,021, the second-most in the history of the Boston Celtics.